1. Field of the Invention
The invention concerns a component of an internal combustion engine of the generic type defined in greater detail hereinafter. The invention further concerns a process for production of a component of an internal combustion.
2. Description of Related Art
DE 199 02 884 A1 discloses a piston for an internal combustion engine with direct injection as well as a process for production thereof, in which the collar of the cavity edge is melted and an additive is supplied to the melt. The goal of this addition of additive is to increase the stiffness and temperature resistance of the piston in this area which is highly stressed thermally as well as mechanically, in order to be able to employ the piston in environments with higher temperatures and pressures.
Similar methods for producing a higher stability in a high stressed area are described in DE 1 122 325 A1, DE 2 124 595 A1, DE 28 35 332 C2 or DE 2 136 594 A1.
From EP 0 092 683 B1 or DE 199 12 889 A1 processes for production of valve seats are known, in which likewise one or more strength increasing additives are introduced into a molten area, in order to achieve higher hardness of this area.
The problem with many of these components, as well as the processes employed for manufacture thereof, is that with an increase in the stiffness, with to the accompanying increase in brittleness of the material, upon exposure to thermal loads or in the case of an overlap of thermal and purely mechanical loads formation of cracks can occur as a result of material fatigue. This applies in particular when a thermally high loaded area is also subjected, in addition to this thermal load, to strong temperature fluctuations, for example as a consequence of liquid cooling.
In accordance with the conventional state of the art, attempts have been made to solve the problem by improving the casting techniques and using a subsequent thermal treatment to set up a fine and stable as possible micro structure. These measures however influence the entire component, so that the above-described problems cannot be overcome thereby.